tmn, if you want spring blooming types, the "April" series are a good choice. Most are rated for zone 6. If you have a spot that is protected from winter wind, that's a plus. Also, they get burned by winter sun, so you need to keep them in a shaded spot, keeping in mind the changes in the angle of the sun throughout the seasons. A spot that is a bit warmer, such as near a stone wall or house, foundation, etc. that may hold a little heat is a help as well. I don't do anything special in winter, unless there is a heavy snow load that could break the branches. This past winter was especially brutal, and much of the tops of my plants (6-7 feet tall ones) were burned, and the buds in those parts were killed. The parts that were buried in snow for a few weeks are fine, and the flowers bloomed as always. The new growth in the "good" parts is moving along normally, healthy green shoots. But in the damaged parts of each plant, only now do I see some tiny green shoots. I am sure the plants will recover this year but it will be another few weeks before the damaged areas start to look good again. There are also many fall blooming types, which are generally a bit hardier than the spring blooming ones, and you don't have to worry about the buds being killed in a cold winter, since they form during summer and then bloom in fall. Good luck with yours! I'd like to know how they do for you.

In cold Zone 6 in the NE, established/new camellias may sometimes temporarily loose leaves after very cold temperature drops, just like other shrubs do but they will leaf out later when temps warm up. But in Z7B, if there are no injuries, it would be a bit rare unless there were big dips. I have not had foliage issues due to temperatures as cold as 13F in January but, if a new, not-yet-established camellia did not have enough soil moisture before these wild temperature dips, it may have started leaf browning issues. Your big dips probably happened in Nov 22-23 ish; and Jan 21, 30-31-ish. The single digits in January of this year probably caused the problem for this shrub. Lack of sufficient soil moisture in the top 4" in a dry (warm or cold) winter may cause leaf drop. To prevent the loss of leaves and-or buds, I water deeply & mulch on the night before those very cold, wild temperature dips; or that you water on dry, warm winters where the soil has not frozen;.I maintain 2-4" of organic mulch. When I turned off the drip irrigation once during winter.... and forgot to turn it back on... I started to get browning of leaves during dry, warm, late winter months. Then, as blue bayou mention, there are leaf pests.... :o(... double sigh.... although they eat the leaves and not make a leaf suddenly turn brown without injuries unless a branch was eaten/damaged further below. Remember that this is a newly planted shrub so it needs to get water where the pot's potting soil is located. When watering, start near the base and water outwards around it and water only the soil, not the leaves. You can very carefully and lightly scratch some branches to see if you see "green". It should be time for leaf out this month. I suspect your are probably close to being done with frigid temps. Knock on wood!

Not necessarily as they must have come from somewhere else. I would have sprayed horticultural oils during the dormant season (winter) and then either horticultural oils or insecticidal soaps during the growing season to suffocate them. I would then plan on repeating them one or two more years and see if they are not needed afterwards. These are common pests in the northeast. They "appear" in hydrangeas around mid May or later and then move on to camellias later on as they move to warmer areas. https://extension.umd.edu/hgic/topics/cottony-camellia-scale-shrubs

I'm not going to go look it up, but isn't Cleveland considered a smidge milder than Cincinnati? Dave your advice on taking guidance from public arboreta is very thoughtful; that being said, I'd tell people not to put all their plant selection eggs in that basket either. As with anything run by humans, public gardens seem to have their own agendas and biases. And those evolve with whatever personalities currently hold sway over the place - look at what happened to "The Garden Formerly Known As Quarryhill". And then there's the anecdote I love to make a pest of myself by repeating, about Longwood Gardens screwing up their at first attempt to re-establish a camellia they'd actually bred in the 1960s! Which leads me to my final advice to Harry or anyone else trying to establish BLEs in borderline too cold climates. DO NOT SPOIL THEM WITH FERTILIZER. And to a lesser degree, anything close to overwatering. You need them to start establishing the best root system, early on after planting...not a lot of soft top growth. I'm convinced they are more likely to do that if they don't have everything they need dumped into the little 'bathtub' formed by the container's potting soil. My climate in the grand scheme of things isn't too different from LW. I have it from the horse's mouth: their erstwhile Camellia specialist and breeder wanted to get 'Aida' established quickly to cross with it. He heavily fertilized a cutting planted in maybe 2011, to get a large plant. It was 4' by Polar Vortex I.* (2013-2014) My plant had a little head start - maybe I planted in 2009. (There was fanfare at the time that Rarefind in NJ was the first to re-introduce it to commercial horticulture.) But I didn't fertilize it, or at worst was very stingy like a couple sips of standard MG dilution, and mine got to roughly 4' too, in almost twice the time. You can guess where this is going? Theirs was planted in a non-public area sheltered by production greenhouses on three sides. That certainly should have made up for the fact I have container ship navigable water roughly a mile or two from me. Mine was in a relatively cold and unsheltered part of my garden - especially back then before any of my conifers had grown. Mine had minor leaf edge burn that winter...just a little reddish brown singe, barely noticeable. Theirs was totally incinerated - not even able to come back from the roots!!! I've seen this time and again with my own plants. If I try to speed up the growth of a borderline BLE, even a little, it's more likely to collapse when stressed by various things, either drought or cold. * NB that he expressed an understanding of the risk he was taking to push it along like that; he did have a terminal degree in horticulture.